piha.lc / beta.piha.li + company_site marketing landing (#4)

## Summary

- Public short domain is **`piha.lc`** (prod) and **`beta.piha.li`** (beta)
- `/` is a marketing page in [aimloperations.com](https://aimloperations.com) / `company_site` styling (Inter, dark, cyan)
- CTA: want access → [contact](https://aimloperations.com/contact)
- Nav/logo/footer match the company site; debug mint form uses the same chrome

Closes #3.

## Secrets (control node)

Update hostnames only — no new token/pepper unless you are rotating:

**`url_shortening_service_prod.env`**
```text
DJANGO_ALLOWED_HOSTS=piha.lc,shortener.aimloperations.com,url-shortener,web
SHORT_DOMAIN=piha.lc
PUBLIC_SHORT_URL=https://piha.lc
SHORT_PUBLIC_HOSTS=piha.lc
CONTACT_URL=https://aimloperations.com/contact
```

**`url_shortening_service_beta.env`**
```text
DJANGO_ALLOWED_HOSTS=beta.piha.li,shortener-beta.aimloperations.com,url-shortener,web
SHORT_DOMAIN=beta.piha.li
PUBLIC_SHORT_URL=https://beta.piha.li
SHORT_PUBLIC_HOSTS=beta.piha.li
CONTACT_URL=https://aimloperations.com/contact
```

NPM: `piha.lc` / `beta.piha.li` → this container. Still do not proxy `/api/` on the short host.

## Test plan
- [ ] `cd site && uv run python manage.py test`
- [ ] `GET /` looks like aimloperations.com; Request access / Contact go to aimloperations.com/contact
- [ ] `GET /<code>` still 302
- [ ] `/api/` on Host `piha.lc` is 404

Reviewed-on: #4

README.md

@@ -125,7 +125,7 @@ short URL, logs, or git.
 
 Two NPM hosts, same container `WEB_PORT` (default 8005 prod / 8015 beta):
 
-1. `SHORT_DOMAIN` (`aiml.pw` / `cidinn.li`) — `/` landing + `GET /[a-z0-9]{4,8}`.
+1. `SHORT_DOMAIN` (`piha.lc` prod / `beta.piha.li` beta) — `/` landing + `GET /[a-z0-9]{4,8}`.
    Drop `/api/`, `/admin/`, `/debug/`.
 2. API hostname — proxy `/api/` only. Drop `/admin/`. Add that Host to
    `DJANGO_ALLOWED_HOSTS` and `SHORT_API_HOSTS`.